Community-acquired methicillin-resistant Staphylococcus aureus in children with no identified predisposing risk

Context.-Community-acquired methicillin-resistant Staphylococcus aureus (MRSA) infections in children have occurred primarily in individuals with recognized predisposing risks. Community-acquired MRSA infections in the absence of identified risk factors have been reported infrequently. Objectives.-To determine whether community-acquired MRSA infections in children with no identified predisposing risks are increasing and to define the spectrum of disease associated with MRSA isolation. Design.-Retrospective review of medical records. Patients.-Hospitalized children with S aureus isolated between August 1988 and July 1990 (1988-1990) and between August 1993 and July 1995 (1993-1995). Setting.-The University of Chicago Children's Hospital. Main Outcome Measures.-Prevalence of community-acquired MRSA over time, infecting vs colonizing isolates, and risk factors for disease. Results.-The number of children hospitalized with community-acquired MRSA disease increased from 8 in 1988-1990 to 35 in 1993-1995. Moreover, the prevalence of community-acquired MRSA without identified risk increased from 10 per 100 000 admissions in 1988-1990 to 259 per 100 000 admissions in 1993-1995 (P<.001), and a greater proportion of isolates produced clinical infection. The clinical syndromes associated with MRSA in children without identified risk were similar to those associated with community-acquired methicillin-susceptible S aureus. Notably, 7 (70%) of 10 community-acquired MRSA isolates obtained from children with an identified risk were nonsusceptible to at least 2 drugs, compared with only 6 (24%) of 25 isolates obtained from children without an identified risk (P=.02). Conclusions.-These findings demonstrate that the prevalence of community-acquired MRSA among children without identified risk factors is increasing.